Using the nanometer probe available in the dedicated scanning transmission electron microscope (STEM) local structural information can be obtained from individual layers in  grown Si-Si1-xGex multilayer structures. Furthermore the small probe size enables cleaved specimens with their very large wedge angles to be analyzed in cross-section. Diffraction patterns are shown from multilayers of varying periodicity. Analysis of the patterns concentrates on the higher order Laue zone (holz) reflections in the high angle excess ring . The behaviour of the excess holz reflections indicates the transition from a strained layer superiattice to a dislocated structure as the thickness of the layers increases for a given composition.